Phyrexian Tower #248 from Ultimate Masters is a rare card that currently sells for about $28.29 ungraded, with graded copies ranging from $19.99 at grade 9.5 to $32.66 at grade 10. A grade 10 copy sells for around $32.66 vs $28.29 raw. That's a modest premium, so grading only pays off for near-perfect copies.